


Buffer Overflow

by HushBugger



Category: Undertale (Video Game)
Genre: Bug Abuse, Gen
Language: English
Status: Completed
Published: 2021-03-07
Updated: 2021-03-07
Packaged: 2021-03-13 17:41:27
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,378
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29904702
Author URL: https://archiveofourown.org/users/HushBugger/pseuds/HushBugger
Summary: Frisk resets one too many times, and the world goes haywire.
Relationships: Flowey & Frisk (Undertale)
Comments: 1
Kudos: 11





	Buffer Overflow

## I

The human drew a wide rectangle in the snow with their stick. A stroke split it in two. 

“This is the world,” they said. “Here on the right is where all the concepts live. The platonic realm. Thingspace.” They drew a stylized house, a chair, a flower. “It’s static. Completely frozen. Everything exists and nothing happens.” 

“Now here on the _left_ ,” they gestured, “is where events live. Spacetime. It’s where things change and interact. Let’s say the flower, uh, enters the house, and sits down on a chair.” As they talked they sketched it, all the way to the side. “Are you with me so far?” 

Flowey studied the new drawing. The flower’s roots dangled over the edge of the seat, as if they were legs. “Good job, champ,” he said. “Have you considered becoming a painter?” 

“Okay,” they said, ignoring the taunt. “Now what happens if you create a save file?” 

Flowey stared at the human. This was a pretty casual way to bring up that subject. 

“Come on,” they said. “We both know that we both know. No need to pretend.” 

He turned back to the drawing. “It…keeps a snapshot?” 

“Close. It _does_ make a copy, but it’s the copy that starts moving, while the original stays still.” They copied the flower and the chair and the house a little to the right, and changed the flower to wave at the viewer. “And then, when you load the file…” They flattened the snow with an arm. “You go back to the original.” 

“And how do you know this?” 

“I’m getting to that! So let’s say you save, and then you save again, and again. Each time you save, you move to the right.” They re-drew the flower, then drew another, and another, making a tidy row of flowers. “You keep doing that until you’ve filled up Spacetime, and you’re up against the wall of Thingspace. What happens if you save one more time?” 

“I’m going to guess you end up wherever the hell we are now.” 

The human nodded. They looked rather smug. 

Behind them, most of the world had dissipated into a thick dark mist. Nothing was visible a few feet beyond the edge of the clearing. 

Objects slowly descended from the black sky along perfectly vertical tracks. A mailbox; the “Welcome to Snowdin” sign; a spread-eagled bunny with glassy eyes. An endless procession of entities sank down, then through the ground, without leaving a trace. 

“By my count it took about sixty-five thousand saves to get here. Give or take.” 

“So what the hell are we looking at?” 

“We’re in Thingspace. And these are the things. Not those pale facsimiles you see every day, but the _concepts_. Like, this stick I’m holding is just _a_ stick, an instance of a stick. It’s a pointer to the _true_ stick, which exists somewhere in the cloud around us. And you’re an instance of Flowey, a label that says ‘Flowey’, just as I am a label that says ‘Frisk’. 

“Frisk? Is that your name?” 

“It is.” 

Flowey felt foolish for hoping different. “Never mind.” 

“Though we’re not _just_ labels. We’re our memories, too. And if I break this stick the true stick stays whole, so the brokenness is part of Spacetime. But if the _true_ stick were broken, my instance of a stick would be broken too.” 

“Okay. So what now?” 

“Now? I’m going to save the world.” 

## II

Flowey was distracted. He shouldn’t have been, this was something he couldn’t afford to give away. But he couldn’t stop his eyes from tracking the form of a child with a striped shirt and white floppy ears. 

Asriel. 

Even with its limbs spread and its face blank the body looked innocent and naive. 

Frisk followed his gaze. “Ah,” they said. “That’ll come in handy.” 

They waited for it to drift down, then grabbed it by an ankle. Its vertical movement stopped, leaving it hanging in the air. 

“There. We’ll just keep this around for later.” 

They didn’t acknowledge Flowey’s connection to Asriel. But they clearly knew. And Flowey hadn’t told them. 

“Have you…been here before?” Flowey asked. 

“If you mean here, in Thingspace, then no, this is the first time,” said Frisk. 

They looped a piece of string around a leg, and tied a knot. 

“But if you’re asking if I’ve been in the underground before, and you don’t remember it, then the answer is yes. I’ve been here many times.” 

“Then _why_ don’t I remember?” 

For the first time, Frisk hesitated. “You didn’t want to,” they said. 

“No. You’re messing with me, I can tell. What happened?” 

“You wouldn’t believe me. I can’t do it justice.” 

“Try me.” 

They looked up, avoiding eye contact. “You absorbed everyone’s souls. You regained the emotions you lost. You broke the barrier. And then you gave it all up.” 

“I wouldn’t do that.” 

“Guess you had to be there.” 

“So. Happy ending. Why did you come back?” 

“That’s just it, isn’t it? Endings.” Frisk looked wistful. “When we left, that was it. That was the end of everything real. I have a few scattered memories from after that—a winter party, and something about Papyrus’s favorite food, for some reason—but I’m not even in them.” They started shaking slightly. “Do you know what it’s like to not feature in your own memories? The only—the only thing I remember _doing_ was deciding to go back. And I did it all over again, and the same thing happened. And again. And again. This is the only place that _exists_.” 

They gestured at the torrent of objects. “Do you see anything that looks like it’s from the surface? These concepts make up everything that exists—no, everything that _can_ exist—and it turns out all of it’s in the underground. Nothing on the surface is real. If we leave, we’re done for.” 

“Y-yeah, right. I’ve gone to the surface, you know. It sure looked real to me.” 

“You _remember_ going to the surface. There’s a difference.” 

“What, nothing’s real unless it happened to you personally?” 

“No. No, come on, think for a moment. I was _born_ on the surface, supposedly. I remember a whole life from before I fell down. I had a home, and parents, and, and—” Frisk swallowed. “But I don’t remember anything from when I went back. Isn’t that suspicious? As far as I’m concerned, all that’s real is what I can still do. I can go anywhere in the underground. I can go back to the moment I fell down. But I can’t go any earlier, because that time doesn’t exist. And I can’t go to the surface, because that place doesn’t exist.” 

Frisk looked almost comical as they ranted, holding an inert Asriel by a string like a balloon. But Flowey didn’t feel like laughing. 

## III

“Everything is a pointer. And pointers point at _locations_ , not things. So we can change instances in Spacetime just by swapping concepts in Thingspace.” 

Flowey had to mull that over for a bit. He was begrudgingly hanging onto Frisk’s arm, as burrowing underground would make conversation difficult. “Hang on,” he said. “Is that why you’re dragging around Zombie Asriel over there? You’re gonna—you’re gonna find the concept of Flowey, and swap in the concept of Asriel, and poof?” 

“Pretty much. Keep an eye out, will you?” 

That was a plan he could get behind. He was getting tired of being a flower. 

Frisk was following a circuitous route through Snowdin’s forest. Flowey hadn’t seen a single other person, not even when crossing a path. 

“Where is everyone?” 

“I’m doing my best to avoid people, so they don’t get pulled in. I _think_ that, since we’re the only entities with memory that persists across resets, events will be borrowed from previous timelines if we don’t interfere with them. But if I’m wrong—” 

Flowey tightened his grip. “Shut up. Stop. Look over there. Is that…?” 

Buried in the cloud of concepts was a green and yellow speck. “Could be a normal golden flower,” said Frisk. 

They plodded through the thicket until the concept was directly overhead. From this angle they could see that the flower had a shifting constellation of blots between its petals, more a Rorschach test than a face. But that was about right. 

He really, really hated this body. 

Flowey slid off Frisk’s arm, and Frisk undid the string around the Asriel. The flower descended agonizingly slowly. 

When it was within reach, Frisk pushed it out of the way with the concept of Asriel. 

The change was instantaneous. A loud bang, a jerk in perspective, and all of a sudden he had two feet buried in the soil and two arms flailing around. It felt as if something was forcing its way up his throat, and he started to heave, but nothing came out. He forced his eyes shut. 

When he opened them, he found Frisk standing over him, looking concerned. He felt a flash of… 

He didn’t know. Fondness? Irritation? This would take some getting used to. 

He opened his mouth to say he was alright, but was immediately distracted by his having a tongue, and teeth. Had it always been like that? This busy? As a flower he had just made words happen. This was ridiculous. “I’m okay,” he managed. 

He took Frisk’s extended hand, lifted himself up, and immediately fell over. 

## IV

Alphys kneaded her forehead with her stubby fingers. “Okay, let me see if I’ve got this right. You broke the world first, on purpose, and _then_ you came to ask me if I could fix it?” 

“But you can, right?” asked Frisk. 

“Why—why would you assume that I can fix this? Why would you assume that _anyone_ can fix this? Like, yeah, I do know some stuff about physics, and, and about computers, but this isn’t anything like that! For a start—” 

Asriel had experience negotiating inconvenient facts with Alphys. She’d have to ramble on for a while. It was her way of processing world-shaking ideas. To her credit, she did always end up comprehending them, even when others would reject them or take them on faith. That made her interesting to toy with. 

This idea had hooked her good. She hadn’t even asked who he was, though she made occasional worried glances. She’d probably figure it out on her own, given enough time. 

The three of them were seated in her lab, Alphys in her desk chair, he and Frisk on the ground. It was air-conditioned, thankfully—he had forgotten how terrible fur was in Hotland’s heat. 

He zoned out as Frisk explained time travel and the fundamental nature of the cosmos. This stuff was _tedious_. 

“—not mean fixing the corruption, I think I can do that by loading a save,” they said. “But before I do that I want to change the course of the timeline. It always ends when we leave the underground, and there’s no way to avoid it, no way to permanently stall it. I want to derail it so badly that leaving isn’t an option.” 

“But anything we do now will be undone if you load, right? I won’t even remember this conversation, which—which I’m not too happy about, to tell you the truth—” 

“Not changes to Thingspace.” 

“Right, right. So—you want to, you want to destroy the exit?” 

Asriel was struck by a memory of Toriel pacing through a hallway. 

“I don’t know if that’ll be enough. My thinking was, you have cameras set up all over the place, can you see anything anywhere that might help?” 

They walked over to the viewing screen. Alphys pressed a button, and it flickered to a scene in Snowdin, suffused with floating objects, none of which looked interesting. She switched to another view. And another. And— 

“Hold on,” said Asriel. “What’s that?” 

She switched back, to a view of the garbage dump. Something grey was spread across the entire left edge of the screen. She rotated the camera. 

It was a building. Not a monster building, nobody built like this in the underground. It was a roomy, modern office building, many stories high, with lots of glass. 

Frisk’s jaw dropped. “I—I recognize this place. But how…” 

Alphys switched to a nearby camera. The building still didn’t fit on the screen, but it was joined by other buildings—as well as many floating human bodies. 

“This is from my home town. I thought it wasn’t real.” 

They sat down with their back against the wall. 

“There is one final moment, always, before we leave. We’re standing right outside the exit, watching the sun rise. And in the distance, there’s the town, rising into the sky. All this time I thought it was just scenery. A prop. But it exists. It actually _exists_.” 

## V

The view as the drone swept over the landscape reminded Asriel of how _big_ the surface was. It was ridiculous how much empty space there was, even when viewed remotely through a shaky camera. 

There were anomalies. From this angle there was a disconcerting blank white gap between the sky and the horizon. It appeared that, while the town was real, most of the surface wasn’t. 

But the town did appear solid. And its people were visible as little crawling specks. 

It had taken an unreasonable amount of work to even get to this point, where none of them had left the mountain yet. They had had to find the concept of the barrier and replace it by a potted plant, travel back in time, explain everything to Alphys again, explain everything to everyone else… 

He had had to introduce himself to his parents. And this time there were no do-overs. 

But now everyone was crammed behind a computer screen, waiting breathlessly. Toriel tolerated Asgore’s presence and Papyrus looked ready to explode. Even Sans was keeping his eyes open. 

The drone went soaring through the streets. It drew a few looks from passersby, but nobody could know what it represented, and in any case they were distracted by the seemingly-sudden disappearance of the rest of the world. But yes—the town was real. 

Asriel tore his eyes away to study Frisk’s face. They looked enraptured, elated, yearning. 

They were going home. 


End file.
